When a neighbor’s tree falls onto your house, vehicle, fence, or other property, one of the first questions is usually simple:
Who is responsible for the damage?
The answer, however, is rarely determined by which side of the property line the tree came from.
From an arboricultural standpoint, some of the most important questions are what condition the tree was in before it failed, whether warning signs were present, whether those conditions were reasonably observable, and what actually caused the tree to fall.
Those questions can become especially important when an insurance claim, subrogation investigation, or legal dispute follows the failure.
A Fallen Tree Does Not Automatically Mean the Tree Owner Was Negligent
Trees can fail unexpectedly.
A healthy tree or branch can fail during an unusually severe weather event without there having been an obvious reason to remove it beforehand. Conversely, a tree may fall during relatively ordinary weather because it was already structurally compromised by decay, root damage, poor architecture, or another pre-existing condition.
That distinction matters.
The fact that a tree fell during a storm does not, by itself, tell us why the tree failed.
A forensic arboricultural investigation looks beyond the timing of the event and examines the physical evidence.
Was the Tree Defective Before It Fell?
One of the first things I evaluate following a tree failure is whether there is evidence of a pre-existing defect or condition that contributed to the failure.
Depending on the tree and type of failure, that evidence may include:
- Internal or external decay
- Cavities or hollow areas
- Dead or declining portions of the canopy
- Fungal fruiting bodies
- Cracks or previous structural failures
- Codominant stems or weak branch unions
- Included bark
- Root decay or root loss
- Construction damage
- Severed roots
- Soil compaction or grade changes
- Excessive canopy imbalance
- Previous improper pruning
Some conditions are readily visible from the exterior. Others may require closer examination, diagnostic testing, excavation, or analysis of the remaining stump, root plate, trunk, or failed portion of the tree.
This is why photographs taken immediately after a failure can become extremely valuable.
Could Someone Have Known the Tree Was Dangerous?
Finding a defect after a tree has failed is only part of the investigation.
Another important question is whether there were observable warning signs before the failure occurred.
For example, extensive decay that becomes visible only after a trunk breaks may be very different from a large cavity, fungal fruiting bodies, significant canopy dieback, or an obvious crack that had been present and visible for an extended period.
In forensic tree investigations, I often evaluate not only what defect existed, but also:
Was there evidence that the condition existed before the loss?
Would it have been reasonably observable during an appropriate inspection?
Were there symptoms that should have prompted further evaluation by a qualified arborist?
These questions can help attorneys, insurance professionals, property owners, and other parties better understand the circumstances surrounding the failure.
Did the Storm Actually Cause the Tree to Fall?
Weather data is another important piece of the puzzle.
It is common to hear that a tree was “blown over by the storm.” Sometimes that is exactly what happened.
Other times, weather may simply have been the trigger that exposed an existing structural problem.
As part of a forensic investigation, reported wind speeds and weather conditions can be compared with the physical evidence remaining at the site.
If numerous otherwise healthy trees in an area failed during an extreme wind event, that tells one story.
If one severely decayed tree failed while surrounding trees remained intact during relatively moderate winds, that may tell a very different story.
The objective is not to assume that the weather caused the failure simply because the two events occurred at the same time.
The objective is to determine the most reasonable explanation supported by the available evidence.
The Failure Point Can Tell Us a Lot
When possible, I want to examine the actual location where the tree failed.
A tree uprooted from the soil presents different evidence than a trunk that fractured several feet above grade. A failed branch union presents different questions than a decayed root system.
The fracture surface itself can sometimes reveal important information.
Decay patterns, remaining sound wood, root condition, old wounds, fungal activity, cracks, included bark, and other structural characteristics can help reconstruct what happened.
This is one reason I recommend preserving evidence whenever a significant tree failure may result in an insurance or legal dispute.
Removing the tree is often necessary for safety and access, but photographs and documentation should ideally be obtained before the evidence is hauled away or destroyed.
What Should You Document After a Neighbor’s Tree Falls?
If a tree failure has caused significant property damage, documentation should begin as soon as it is safe to do so.
Photograph the entire scene before cleanup begins whenever possible. Take wide photographs showing the tree in relation to the surrounding property as well as close-up photographs of the failure point.
Photographs of the stump, root plate, broken trunk, branch unions, cavities, decay, fungal growth, and failed wood can all become important later.
It can also be useful to preserve:
- Photographs from before the failure
- Security-camera or doorbell-camera footage
- Previous tree-service estimates or inspection reports
- Written communications concerning the tree
- Photographs showing previous dead limbs, cavities, leaning, or decline
- Weather information from the date and approximate time of failure
For larger losses, early documentation can make a substantial difference because much of the physical evidence disappears during cleanup.
What Does a Forensic Arborist Actually Determine?
A forensic arborist is not there simply to say that a tree fell.
The assignment is to reconstruct the circumstances surrounding the failure using arboricultural evidence.
Depending on the case, that may include evaluating the species and condition of the tree, examining the failure point, identifying decay or structural defects, evaluating the root system, reviewing photographs taken before and after the loss, considering maintenance history, reviewing construction or site disturbance, and comparing physical findings with reported weather conditions.
In insurance and legal matters, the goal is to provide an independent, evidence-based opinion regarding the condition of the tree and the factors that most likely contributed to its failure.
That distinction can become particularly important in subrogation matters where an insurance carrier has already paid a property-damage claim and is investigating whether another party may have contributed to the loss.
Sometimes the Most Important Evidence Existed Before the Tree Fell
One of the biggest challenges in tree-failure investigations is that the tree is often removed before anyone considers having it evaluated.
By the time an arborist becomes involved, the stump may have been ground, the failed portions removed, and the site cleaned.
That does not necessarily make an investigation impossible.
Historical photographs, Google Street View imagery when available, property photographs, inspection records, tree-service documentation, witness photographs, weather records, and photographs taken immediately following the loss can sometimes provide substantial evidence about the tree’s pre-loss condition.
The earlier a forensic arborist becomes involved, however, the more physical evidence can usually be preserved and evaluated.
The Question Is Usually Bigger Than “Whose Tree Was It?”
When a neighbor’s tree damages another property, determining where the tree originated is relatively straightforward.
Determining why it failed can be much more complicated.
- Was the tree reasonably healthy before an extraordinary weather event?
- Was there advanced decay or another structural defect?
- Were warning signs present?
- Was the root system damaged by construction or excavation?
- Had portions of the tree previously failed?
- Were the conditions visible before the loss?
- Did the reported weather reasonably explain the failure?
- Those are questions that should be answered from evidence rather than assumption.
Need an Independent Tree-Failure Evaluation?
Arborist On Demand provides independent forensic tree investigations, cause-of-loss evaluations, tree and plant appraisals, and expert consulting for insurance carriers, subrogation professionals, attorneys, property owners, and other parties throughout the United States.
Many cases can be evaluated digitally using photographs, video, records, weather information, and other available evidence. On-site investigations are also available when the circumstances require physical examination or testing.
About the Arborist
Matt Latham is an ISA Board Certified Master Arborist®, ASCA Registered Consulting Arborist®, and Tree & Plant Appraisal Qualified professional with more than 20 years of experience in arboriculture. He specializes in forensic tree investigations, tree and plant appraisals, tree-risk assessment, and expert consulting involving property damage, insurance claims, subrogation, and litigation.
Through Arborist On Demand, Matt provides independent arboricultural opinions for insurance professionals, attorneys, property owners, municipalities, and other clients throughout the United States. His work focuses on identifying the physical evidence, determining probable causes of tree failure or loss, and communicating those findings in clear, defensible reports.
Matt Latham – in**@**************nd.com
ISA Board Certified Master Arborist®
ASCA Registered Consulting Arborist®
Tree & Plant Appraisal Qualified
713.385.7040 | www.arboristondemand.com
Arborist On Demand
Independent Forensic Tree Consulting for Insurance, Legal & Property Claims
